Results using an optical approach to study patterns of cortical organization suggest that response properties in addition to ocular dominance and orientation may be organized laterally (tangentially). Funds are requested in the present proposal to continue this analysis, using optical imaging to find functional organizations that are then explore in greater detail with microelectrodes. In one group of experiments, cortical magnification will be determined optically along different axes so that anisotropies related to ocular dominance and orientation can be determined. In light of the recent convergence of findings from different labs obtained with somewhat different techniques, funds are also requested to compare results obtained from the same cortical regions before and after the application of voltage sensitive dye. These experiments are designed to increase our understanding of visual information processing and associated structure-function relationships in the upper layers of monkey striate cortex.